1. Field of the Invention
This invention relates to novel alpha-methylstyrene-conjugated diene oligomer dilithium as a polymerization initiator. In one aspect, the invention relates to a process for preparing novel alpha-methylstyrene-conjugated diene oligomer dilithium as a polymerization initiator for a living polymerization.
2. Description of the Prior Art
It is well know that organodilithium initiators are used as initiators for the living polymerization, in general, and A. C. S. Polymer Preprints, Vol. 10, No. 2, P 837 (1969) and British Pat. No. 1264741 disclose a preparation of alpha-methylstyrene oligomer dilithium as a polymerization initiator, but the active lithium linking and the terminals of the initiator is very unstable. For example, the initiator loses the greater part of its activity after 24 hours at 25.degree. C. Moreover, the initiator is not soluble in a non-polar solvent, and unreacted alpha-methylstyrene monomer remains in the initiator. Concequently, the initiator is not suitable for a living polymerization as a polymerization initiator. Further, U.S. Pat. No. 3,091,606 discloses a process for solubilizing a polymerization initiator by the addition of dienes. However, in a process where a diene is added all at once, it is impossible to obtain a stable active terminal lithium because gellation occurrs.